Runtime v2

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

runtime/v1/linux/proc/exec.go

@@ -0,0 +1,226 @@
+// +build !windows
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package proc
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sync"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+
+	"github.com/containerd/console"
+	"github.com/containerd/containerd/runtime/proc"
+	"github.com/containerd/fifo"
+	runc "github.com/containerd/go-runc"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+)
+
+type execProcess struct {
+	wg sync.WaitGroup
+
+	proc.State
+
+	mu      sync.Mutex
+	id      string
+	console console.Console
+	io      runc.IO
+	status  int
+	exited  time.Time
+	pid     int
+	closers []io.Closer
+	stdin   io.Closer
+	stdio   proc.Stdio
+	path    string
+	spec    specs.Process
+
+	parent    *Init
+	waitBlock chan struct{}
+}
+
+func (e *execProcess) Wait() {
+	<-e.waitBlock
+}
+
+func (e *execProcess) ID() string {
+	return e.id
+}
+
+func (e *execProcess) Pid() int {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return e.pid
+}
+
+func (e *execProcess) ExitStatus() int {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return e.status
+}
+
+func (e *execProcess) ExitedAt() time.Time {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return e.exited
+}
+
+func (e *execProcess) setExited(status int) {
+	e.status = status
+	e.exited = time.Now()
+	e.parent.Platform.ShutdownConsole(context.Background(), e.console)
+	close(e.waitBlock)
+}
+
+func (e *execProcess) delete(ctx context.Context) error {
+	e.wg.Wait()
+	if e.io != nil {
+		for _, c := range e.closers {
+			c.Close()
+		}
+		e.io.Close()
+	}
+	pidfile := filepath.Join(e.path, fmt.Sprintf("%s.pid", e.id))
+	// silently ignore error
+	os.Remove(pidfile)
+	return nil
+}
+
+func (e *execProcess) resize(ws console.WinSize) error {
+	if e.console == nil {
+		return nil
+	}
+	return e.console.Resize(ws)
+}
+
+func (e *execProcess) kill(ctx context.Context, sig uint32, _ bool) error {
+	pid := e.pid
+	if pid != 0 {
+		if err := unix.Kill(pid, syscall.Signal(sig)); err != nil {
+			return errors.Wrapf(checkKillError(err), "exec kill error")
+		}
+	}
+	return nil
+}
+
+func (e *execProcess) Stdin() io.Closer {
+	return e.stdin
+}
+
+func (e *execProcess) Stdio() proc.Stdio {
+	return e.stdio
+}
+
+func (e *execProcess) start(ctx context.Context) (err error) {
+	var (
+		socket  *runc.Socket
+		pidfile = filepath.Join(e.path, fmt.Sprintf("%s.pid", e.id))
+	)
+	if e.stdio.Terminal {
+		if socket, err = runc.NewTempConsoleSocket(); err != nil {
+			return errors.Wrap(err, "failed to create runc console socket")
+		}
+		defer socket.Close()
+	} else if e.stdio.IsNull() {
+		if e.io, err = runc.NewNullIO(); err != nil {
+			return errors.Wrap(err, "creating new NULL IO")
+		}
+	} else {
+		if e.io, err = runc.NewPipeIO(e.parent.IoUID, e.parent.IoGID); err != nil {
+			return errors.Wrap(err, "failed to create runc io pipes")
+		}
+	}
+	opts := &runc.ExecOpts{
+		PidFile: pidfile,
+		IO:      e.io,
+		Detach:  true,
+	}
+	if socket != nil {
+		opts.ConsoleSocket = socket
+	}
+	if err := e.parent.runtime.Exec(ctx, e.parent.id, e.spec, opts); err != nil {
+		close(e.waitBlock)
+		return e.parent.runtimeError(err, "OCI runtime exec failed")
+	}
+	if e.stdio.Stdin != "" {
+		fifoCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
+		defer cancel()
+
+		sc, err := fifo.OpenFifo(fifoCtx, e.stdio.Stdin, syscall.O_WRONLY|syscall.O_NONBLOCK, 0)
+		if err != nil {
+			return errors.Wrapf(err, "failed to open stdin fifo %s", e.stdio.Stdin)
+		}
+		e.closers = append(e.closers, sc)
+		e.stdin = sc
+	}
+	var copyWaitGroup sync.WaitGroup
+	if socket != nil {
+		console, err := socket.ReceiveMaster()
+		if err != nil {
+			return errors.Wrap(err, "failed to retrieve console master")
+		}
+		if e.console, err = e.parent.Platform.CopyConsole(ctx, console, e.stdio.Stdin, e.stdio.Stdout, e.stdio.Stderr, &e.wg, &copyWaitGroup); err != nil {
+			return errors.Wrap(err, "failed to start console copy")
+		}
+	} else if !e.stdio.IsNull() {
+		fifoCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
+		defer cancel()
+
+		if err := copyPipes(fifoCtx, e.io, e.stdio.Stdin, e.stdio.Stdout, e.stdio.Stderr, &e.wg, &copyWaitGroup); err != nil {
+			return errors.Wrap(err, "failed to start io pipe copy")
+		}
+	}
+	copyWaitGroup.Wait()
+	pid, err := runc.ReadPidFile(opts.PidFile)
+	if err != nil {
+		return errors.Wrap(err, "failed to retrieve OCI runtime exec pid")
+	}
+	e.pid = pid
+	return nil
+}
+
+func (e *execProcess) Status(ctx context.Context) (string, error) {
+	s, err := e.parent.Status(ctx)
+	if err != nil {
+		return "", err
+	}
+	// if the container as a whole is in the pausing/paused state, so are all
+	// other processes inside the container, use container state here
+	switch s {
+	case "paused", "pausing":
+		return s, nil
+	}
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	// if we don't have a pid then the exec process has just been created
+	if e.pid == 0 {
+		return "created", nil
+	}
+	// if we have a pid and it can be signaled, the process is running
+	if err := unix.Kill(e.pid, 0); err == nil {
+		return "running", nil
+	}
+	// else if we have a pid but it can nolonger be signaled, it has stopped
+	return "stopped", nil
+}